The HMO Cancer Research Network (CRN) was established in 1999 to help the National Cancer Institute maximize the potential of health care delivery systems to address important questions in cancer prevention and control. The CRN consists of an infrastructure and five projects with cover the spectrum of cancer control from prevention to survivorship. Our infrastructure leverages the unique composition and features of the health care delivery systems that comprise this consortium; the 13 health care systems that comprise the CRN consortium are distinguished by their mature automated data systems, commitment to public domain research, and diverse populations. The proposed application is designed to build on the productive cancer research consortium that was established and grown between 1999 and 2006. In this application, we propose to intensify and enhance CRN infrastructure activities that are uniquely positioned to address as yet unsolved issues in cancer care, including: 1) fulfilling the promise of health care informatics to optimize cancer care; 2) improving accrual of adult cancer patients to clinical trials; and 3) understanding the drivers which influence the uptake of innovations in cancer care. The proposed CRN infrastructure will emphasize efficient research methods, identify strategies that contribute to high-quality care, and will maintain a patient-centered perspective. Moreover, with a concerted focus on training of junior investigators, the HMO CRN will utilize the human and technical resources available in its health care systems, to permit exploration and exploitation of ways to improve effectiveness of cancer care. Cancer is a very individual experience. We need ways to address both the impact of cancer at a population level, and ways to help individual patients get the care that is best-suited to their unique needs. To this end, the CRN is designed to increase our understanding of the patient-, clinician- and health plan characteristics that lead to the best possible outcomes in cancer prevention and care.